Field of the Invention
The present invention relates to a method for manufacturing a laminate composed of a flat film being a thin resin film, and a support film being a porous body, and to a laminate preferably manufactured with the manufacturing method.
Related Art
In recent years, self-standing thin films having a large surface area and a thickness on the order of nanometers, and being sufficiently permeable to allow micro substances to pass therethrough, have attracted attention as being usable, for example, as permselective membranes, micro sensors, drug delivery films, etc. For this reason, various studies have been made on methods for manufacturing permeable self-standing thin films; and examples of such methods known in the art include water surface casting methods, interface reaction methods using silane coupling agents, etc. The thin films obtained with these methods, however, generally suffer from problems such as poor mechanical strength, difficulties in increasing the area of the thin film, and limitation on accuracy of the thin film.
Polymer thin films, which are still self-standable with a thickness of 100 nm or less, are known as self-standing films (Patent Document 1). According to the method disclosed in Patent Document 1, polymer thin films are manufactured by providing a sacrificial layer on a surface of a support, subjecting a polymerizable compound in a composition to chain polymerization on the surface of the sacrificial layer, and subsequently removing the sacrificial layer to separate the polymerized composition from the support.
Further, a laminate has been proposed, in which a porous film with a certain level of thickness and a permeable thin film are stacked on top of each other for the purpose of compensating for the strength of the thin film without reducing the permeability of the thin film. A laminate, in which a gas separation membrane (a thin film) composed of polyimide and a thick porous film are stacked on top of each other, has been known as this type of laminate (Patent Document 2).
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2008-285617
Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2015-83296